一种新的低功耗的图象编/解码算法

该文提出了一种改进的低功耗并且只需少量存储空间的图像,视频编码方案,它是基于矢量量化的,K.Masselos等人1998年提出的方案使用了一个小的基本码书,然后通过对基本码书中的每一码字进行八种对称变换,从而把小的基本码书扩展成为一个大的虚码书,补偿了因为码书的尺寸太小而引起的图象质量下降,因为它的基本码书小,从而对存储器的访问次数也就少,那么功耗也就小。同原方案相比,本文做出了如下两个改进:一是基本码书中存放的是码字的经过量化的DCT系数,寻找最佳匹配码字也放在DCT域内进行,二是改进了K.Masselos文中的基本码书的设计方案,消除了码书中存在的重复。改进方案具有计算量更小,操作更灵活的特点。

A MODIFIED ALGORITHM FOR LOW-POWER IMAGE CODING AND DECODING

In this paper, a modified scheme for small memories and low-power image and video coding is presented. It is based on vector quantization. In 1998, K. Masselos uses a small codebook, and by using simple but efficient transformations to the codewords during coding process the small codebook is extended, thus compensated for the quality degradation introduced by the small codebook size. In this way, the power consumption is reduced. Compared to the scheme proposed by K. Masselos, we store the quantized DCT coefficients of codewords in the codebook instead of the codewords itself, and the distortion calculation is performed in the DCT field respectively. Because we use only a part of coefficients to calculate the distances, the distortion calculation is simplified. Furthermore, we modified the way of designing the small codebook; the possible redundancy in K. Masselos's codebook is eliminated.